The present invention relates to a portable data recorder or an imprinter for pressure-transfer printing of embossed data from a relatively rigid substrate onto visually and/or machine readable data sheets. More specifically, the present invention relates to roller-platen imprinters for imprinting by rolling a platen across or over an embossed card or plate with a form set inserted between the platen and the card or plate during operation.
An imprinter is typically used to record information from embossed cards or plates of customers and others at many separate locations, such as retail merchants, service stations and hospitals. Imprinters may be automatic or manually operated for imprinting information embossed on one or more cards or plates onto multipart data sheets known as "form sets". Each form set has sheets of paper interleaved with carbon paper sheets. Information from the cards and plates is transferred by imprinting pressure applied through the form set to the embossed characters on these cards or plates by one or more platen rollers in the imprinter during one or more strokes of the imprinter carriage.
The technology of pressure imprinting of paper documents with carbon ribbons or carbon paper from embossed plates was first used in addressing machines in the 1890's. Imprinters were developed beginning in the late 1920's to repetitively enter address, customer, and other information onto forms in credit transactions, patient identification, and the like. Prior to the availability of imprinters and addressing machines, information was laboriously typed out or written by hand. As a result, errors were numerous, and the cost attendant to preparation and handling of the documents was high. Introduction of mechanical data recorders for use with embossed charge plates helped to avoid the problems of illegible handwriting and inaccurate entry of information in, for instance, retail credit transactions. The resulting sales slips were readily, although manually, processed also reducing the period of time the retail establishment was required to float the transaction.
In the early 1950's, automatic tab card processing machinery for use with optical scanning systems was developed. The petroleum industry, with its particularly heavy credit card volume, was the first to make use of the automatic processing and optical scanning technology. A standardized embossed character was developed for use on credit cards, and imprinters were designed to reproduce these characters with sufficient clarity to permit optical scanning and machine processing. Such systems not only eliminated the previously required manual processing, but achieved a decreased overall document rejection rate from nearly 40% to the 25% range. With this substantial reduction in manual handling, document processing costs were substantially decreased.
Until 1964, virtually all commercial imprinters in use in the United States employed a single platen roller which imprinted data in a single stroke of its platen carriage. Although these imprinters with the single imprinting strokes produced machine scannable documents, and the documents routinely were scanned, the single platen imprinters had a number of disadvantages. Because all lines of embossing on the credit card and station plate were being imprinted at one time on single stroke machines, the force required to move the carriage was high. In addition, the single platen roller often caused smudging on the form set. Further, tilting of the platen roller between the metal station plate and the plastic card left poor impressions in some areas on the form set. Finally, plastic credit cards were often damaged in the single platen imprinters.
This led to a variety of multiple platen and shifting platen designs which allowed for imprinting of the credit card with one platen and the station plate with another.
All of these developments led to a largely satisfactory imprinter design which is now embodied in the Addressograph-Farrington Models Nos. 14-800, 14-850, 14-900 and 14-950 series imprinters. These imprinters are countertop or tabletop machines which include platen assemblies containing rollers of approximately 1-1/2 inches outside diameter and an overall machine weight of 4-10 pounds, depending on model variations. The machines vary in size from approximately 6.times.12.times.4 inches to 6.times.12.times.10 inches, again depending on model variations.
The major disadvantages found in current imprinter design is that the machines are required to be centrally located, not being readily portable. The major advantage of these designs is the overall low rejection rate of scanned documents, which is generally less than 5% due to machine imprint error. While portability of the machine has obvious advantages, such as elimination of a central imprinter location and the lost time associated therewith, a simple reduction in size and weight of the machine is not possible because of the critical interrelationship between size, weight, and function which has developed over the long history of imprinter design.
Specifically, the imprinter design is required to provide a pressure force between the platen and embossed card or plate sufficient to generate a clear, distinct impression of the transferred information so that machine scanning is possible. In order to accomplish this, the machine components must be rigid enough that during imprinting the relationship between the platen, the card or plate, and the base supporting the card or plate remains relatively fixed to guarantee a fairly constant imprinting pressure. In addition, the design must permit the application of imprinting pressure by rolling the platen or platens across the form set and cards with a small enough motive force that it can be easily operated by the average user, i.e., a retail sales clerk.
Over the years, a relatively fixed design constant has developed which is not readily translated into a down-sized and portable model. As weight and size are reduced, rigidity is sacrificed. As rigidity is increased, ease of operation is sacrificed. As rigidity and operation are controlled, down-sizing is sacrificed. As a consequence, no truly portable, lightweight pressure-transfer imprinter has been adopted for use in the credit card industry.
Another problem associated with such pressure-transfer imprinters is the requirement that they operate satisfactorily with embossed credit cards of different thicknesses. For example, the industry-standard thickness dimension for a new credit card is approximately 0.048 inch, but over its useful life the card's thickness may be reduced to 0.040 inch. As a consequence, prior art imprinters have utilized relatively complex design components to accommodate different card thicknesses, and such components have contributed to both the size and weight of the imprinter, making portability of the machines even less practical.